In an upcoming shoot, we'd like to attempt a kind of tricky shot that involves a mirror replacement (i.e. the camera revolves around a mirror, and the reflection inside is shot separately and then composited on top).
Here is a link of the movement we're aiming for:

I'm not sure how to film the movement shot right. Just using tracking markers on the mirror probably won't cut it, because the shot isn't just about matchmoving the reflection to the movement of the camera, but about consistent and jitter-free masking according to the outline of the mirror, which changes throughout. It's also not a matter of corner pinning, since there are no corners.